Hmmmm...   that's difficult ( for me ) - let me share something - and maybe not totally related - but similar ( different string ) - 

I have observed on my FM Concert ( the only "real violin/fiddle" I have - the others are unworthy of mention... ) - I can detect a quite obvious change in sound intensity ( i.e. "ringing" - or lack of it - as you mention ) on the A string when playing around B-flat-C-C#.   This is not "wolfing" - it is "just an unexpected difference in sound volume and sustain" when the note is held

I have researched this, and it appears THAT is not an un-common resonance point in the sound-box.   It is "normal" and, it is (in my situation) understood, and, is now unimportant, and can be catered for in playing ( if / when I need to )

Now - I have - on "Hermano del Diablo" ( my 4/4 violin restrung as a viola ) played with the soundpost ( never felt the need to touch the FM Concert as yet ) - and - my findings on THAT experiment said to me "yes, this can be significant" - so - perhaps - in the fall-to-the-floor - maybe the SP has moved ?    Don't know of course - but it might just be related....   just a guess...  so many things can unexpectedly affect your sound production.   I take it all other strings are fine ?

I would suspect the SP rather than the bow right now... but just a thought????

EDIT: Or, if it was dropped - even a jolt on the bridge ?    Other mechanical aspects ?  Is the E still seated in the nut and bridge grooves and so on... ?  ( I had, un-noticed ) an E ( well, I mean the top string - the A on the viola-strung fiddle ) that was sitting proud of the bridge slot I had cut for it....   took 4 minutes of wondering what was going on until I put my reading-glasses on and discovered it wasn't sitting in the slot - .... take a real close inspection of all mechanical/setup aspects of your fiddle...  question everything... LOL